I would like to remove obsolete simulators from Xcode because I'm low on space. Simulator for iOS 9.1 is 1,46 GB.
Xcode - How to remove simulator
Window > Devices, click on the one you want to delete, click the gear icont at bottom left, choose Delete. Use the + at the bottom left to add a simulator again if you change your mind.
Maybe this:
/Library/Developer/CoreSimulator/Profiles/Runtimes